Bishop Score Calculator

Last updated: April 5, 2026

The Bishop Score Calculator assesses cervical favorability for labor induction using dilation, effacement, station, consistency, and position. A score above 8 indicates favorable cervix; below 6 suggests pre-induction cervical ripening is needed. All clinical decisions require physician evaluation.

Calculator

Cervical Dilationpoints

Effacementpoints

Fetal Stationpoints

Cervical Consistencypoints

Cervical Positionpoints

Results

Bishop Score

pts

Favorable for Induction

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Needs Cervical Ripening

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Points Below Favorable Threshold

pts

Readiness Percent

Results

Bishop Score

pts

Favorable for Induction

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Needs Cervical Ripening

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Points Below Favorable Threshold

pts

Readiness Percent

Not all inductions are equal. Inducing labor on an unfavorable cervix (closed, thick, posterior, firm) is associated with longer labor, higher rates of operative delivery, and increased maternal and neonatal complications. The Bishop score — developed by Dr. Edward Bishop in 1964 — quantifies cervical favorability before labor induction using five cervical examination parameters. The Bishop score calculator provides immediate scoring to guide induction planning. All clinical obstetric decisions require evaluation by qualified healthcare professionals.

Bishop Score Components and Scoring

Parameter	0	1	2	3
Dilation (cm)	Closed	1–2	3–4	5+
Effacement (%)	0–30	40–50	60–70	80+
Station	−3	−2	−1/0	+1/+2
Consistency	Firm	Medium	Soft	—
Position	Posterior	Mid	Anterior	—

Maximum score: 13. Favorable cervix: score above 8. Unfavorable: score below 6. Use this online calculator for immediate Bishop score calculation. All results require physician interpretation.

Clinical Interpretation and Management

Bishop score thresholds and recommended approaches per ACOG guidelines:

Score ≥8: favorable cervix; proceed with oxytocin induction; high probability of vaginal delivery
Score 6–7: borderline; can consider induction but lower success rate; discuss risks and benefits with patient
Score ≤5: unfavorable; cervical ripening recommended before oxytocin. Options: prostaglandins (PGE₁ misoprostol or PGE₂ dinoprostone); mechanical methods (balloon catheter or Foley catheter); combination approaches

Modified Bishop Score and Alternatives

The original Bishop score has been modified (removing station, adding head engagement) in some institutions. The Simplified Bishop Score uses only dilation, effacement, and consistency. The BISHOP's mnemonic (Bish = Bishop score) helps recall: beyond 8 = excellent, similar to spontaneous labor outcomes. Alternatives to Bishop score include: cervical length by transvaginal ultrasound (cervical length below 25 mm predicts induction success comparable to Bishop score above 8); fetal fibronectin testing (negative result predicts low likelihood of delivery within 7 days, may support conservative management). The pregnancy calculators provide complementary obstetric assessment tools. All clinical management requires physician evaluation.

Induction Outcomes by Bishop Score

Original Bishop (1964) and subsequent validation data: cervical score above 9 associated with outcomes equivalent to spontaneous labor onset; score below 5 associated with prolonged induction-to-delivery intervals (above 12 hours) and significantly higher cesarean rates. Meta-analysis (Thokala et al., 2017): each 1-point increase in Bishop score associated with approximately 7% decrease in cesarean delivery risk during induction. For nulliparous women (first-time mothers), the threshold for predicting successful induction is slightly higher than for multiparous women at the same Bishop score.

Visual Analysis

How It Works

Score each of five cervical parameters from your examination: dilation (0–3 points), effacement (0–3 points), fetal station (0–3 points), cervical consistency (0–2 points), and cervical position (0–2 points). Sum all parameter scores for a total of 0–13. Total score ≥8 indicates favorable cervix; ≤5 indicates unfavorable cervix requiring ripening before induction. All results are educational — clinical management requires physician evaluation.

Understanding Your Results

Score 8+: Favorable cervix, high success rate for induction. Score 6-7: Moderately favorable, induction reasonable. Score below 6: Unfavorable, consider cervical ripening before induction. Multiparous women may have successful induction with lower scores.

Worked Examples

Favorable cervix ready for induction

Inputs

dilation2

effacement2

station2

consistency2

position1

Results

score9

favorabilityFavorable cervix

recommendationFavorable for induction - high success rate expected

Bishop 9: cervix 3-4 cm dilated, 60-70% effaced, station -1/0, soft, mid position. Ready for induction.

Unfavorable cervix needing ripening

Inputs

dilation0

effacement0

station0

consistency0

position0

Results

score0

favorabilityUnfavorable cervix

recommendationUnfavorable - consider cervical ripening before induction

Bishop 0: closed, thick, high, firm, posterior cervix. Cervical ripening recommended before induction.

Frequently Asked Questions

A Bishop score of 8 or above indicates a favorable cervix — the cervix is sufficiently dilated, effaced, soft, anterior, and with the fetus engaged to proceed with oxytocin induction with outcomes comparable to spontaneous labor onset. Scores of 6–7 are borderline; induction may be attempted but with lower success rates. Scores of 5 or below indicate an unfavorable cervix where cervical ripening with prostaglandins or mechanical methods is recommended before oxytocin to improve induction success rates and reduce operative delivery risk. This information is educational — all induction decisions require evaluation by qualified obstetric healthcare providers.

Cervical effacement describes the thinning and shortening of the cervix as it prepares for labor. The non-pregnant cervix is approximately 3–4 cm long. As labor approaches, the cervix progressively shortens: 0% effacement = full length (3–4 cm); 50% effacement = half its original length (1.5–2 cm); 100% effacement = completely incorporated into the lower uterine segment ('paper thin'). Effacement is assessed by digital cervical examination — experienced providers feel the cervical canal length and estimate the percentage. Transvaginal ultrasound provides a more objective measurement (cervical length in cm), which correlates with effacement percentage. Bishop scoring: 0–30% effacement = 0 points; 40–50% = 1 point; 60–70% = 2 points; 80%+ = 3 points.

Fetal station describes the relationship between the presenting fetal part (usually the head) and the ischial spines of the maternal pelvis, measured in centimeters. Station 0 = the presenting part is at the level of the ischial spines. Negative stations (−1 to −5) = the head is above the spines; positive stations (+1 to +5) = the head is below the spines, deeper in the pelvis. The Bishop score uses a simplified system: −3 = 0 points; −2 = 1 point; −1/0 = 2 points; +1/+2 = 3 points. Higher station (head deeper in pelvis) indicates better fetal engagement and readiness for delivery, contributing positively to Bishop score. Modern obstetric practice uses a −5 to +5 scale; older texts used −3 to +3.

Yes — Bishop score is a meaningful predictor of cesarean delivery risk when labor is induced. Meta-analysis data show each 1-point increase in Bishop score is associated with approximately 7% lower odds of cesarean delivery during induction. For a nulliparous woman with Bishop score 3 undergoing induction: cesarean rate approximately 40–50%. With Bishop score 8+: cesarean rate approaches that of spontaneous labor onset (approximately 15–20% for nulliparous women). The predictive value is stronger in nulliparous than multiparous women because parous women's cervices tend to respond better to induction at all Bishop scores. These are population statistics — individual outcomes depend on many additional factors. All management decisions require physician evaluation.

For Bishop scores below 6, cervical ripening before oxytocin induction improves outcomes. Pharmacological methods: misoprostol (PGE₁) — vaginal or sublingual administration; very effective but requires careful dosing to avoid uterine hyperstimulation; dinoprostone (PGE₂) — vaginal inserts or gel; slower onset than misoprostol but with more predictable uterine response. Mechanical methods: balloon catheter (Foley catheter placed through cervical os and inflated) — safe for VBAC candidates where prostaglandins are contraindicated; laminaria tents — hygroscopic cervical dilators placed overnight. Combined approaches (balloon plus low-dose misoprostol) are increasingly used. The choice depends on gestational age, urgency, prior cesarean history, and institution protocol. All clinical decisions require physician evaluation.

Multiparous women (with prior vaginal deliveries) typically achieve successful labor induction at lower Bishop scores than nulliparous women, because the previously delivered cervix responds more readily to both mechanical and pharmacological cervical ripening. In multiparous women, a Bishop score of 6 may predict induction success comparable to a score of 8 in nulliparous women. Some practitioners apply modified thresholds: favorable cervix for multiparous women = Bishop score above 6; unfavorable = below 4. Original Bishop score tables were derived primarily from multiparous patients, which is why the thresholds are sometimes considered over-optimistic when applied universally. The ACOG guideline threshold of 8 for favorable cervix is population-level guidance; clinical judgment adjusts for parity. All interpretation requires physician evaluation.

Sources & Methodology

Bishop, E.H. (1964). Pelvic scoring for elective induction. Obstetrics & Gynecology, 24(2), 266–268. ACOG Practice Bulletin No. 107 (2009, reaffirmed 2021). Induction of Labor. American College of Obstetricians and Gynecologists.

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Parameter

Dilation (cm)

Closed

1–2

3–4

Effacement (%)

0–30

40–50

60–70

80+

Station

−3

−2

−1/0

+1/+2

Consistency

Firm

Medium

Soft

—

Position

Posterior

Mid

—

How It Works

Worked Examples

Favorable cervix ready for induction

Inputs

dilation2

effacement2

station2

consistency2

position1

Results

score9

favorabilityFavorable cervix

recommendationFavorable for induction - high success rate expected

Bishop 9: cervix 3-4 cm dilated, 60-70% effaced, station -1/0, soft, mid position. Ready for induction.

Unfavorable cervix needing ripening

Inputs

dilation0

effacement0

station0

consistency0

position0

Results

score0

favorabilityUnfavorable cervix

recommendationUnfavorable - consider cervical ripening before induction

Bishop 0: closed, thick, high, firm, posterior cervix. Cervical ripening recommended before induction.

Frequently Asked Questions